Multi-cylinder engine and method for controlling a number of operating cylinders of a multi-cylinder engine

Multi-cylinder engine and method for controlling a number of operating cylinders of a multi-cylinder engine, wherein fuel is injected by injectors and air intake control is performed by an electronic throttle valve or an idle speed control device. The number of operating cylinders is controlled according to an operating condition, and part of cylinders are rested. Fuel is injected directly into the cylinders by means of said injectors and fuel supply and ignition to the resting cylinders are stopped.